ADRENAL SEX HORMONES

ADRENAL SEX HORMONES

• These are secreted by;a) Zona reticularis (mainly).b) Zona fasciculata (less quantities)• Most of the hormones are male sex hormones

(androgens).• Estrogens and progestrones are also secreted

by adrenal cortex (small quantity).

• Androgens secreted by ad.cortex are;1. Dehydroepiandrosterone.2. Androstenedione.3. Testosterone.• Dehydroepiandrosterone is the most active

adrenal androgen.• The androgens in general are responsible for

masculine features of the body.

• In normal conditions, the adrenal androgens have insignificant physiological effects because of low secretion (low amount) both in males and females.

• In congenital hyperplasia of ad.cortex or tumor of zona- reticularis, an excess amount (quality) of androgens is secreted.

• In males, it does not produce any special effects because large quantity of androgens are produces by testes also.

• In females, the androgens produce masculine features.

• Some of the androgens are converted into testosterone.

• Testosterone is responsible for the androgenic activity in androgenital synd. or congenital ad. hyperplasia.

ADRENOGENITAL SYNDROME

• Under normal conditions, adrenal cortex secretes small quantities of androgens which do not have any significant effect on sex organs or sexual function.

• However, secretion of abnormal quantities of adrenal androgens develops adrenogenital syndrome.

• Some of the androgens are converted into testosterone.

• Testosterone is responsible for the androgenic activity in adrenogenital syndrome.

CAUSE:• It is due to the tumor of zona reticularis in

adrenal cortex.

Symptoms:• Adrenogenital syndrome is characterized by

the tendency for the development of secondary sexual character of opposite sex.

• Symptoms in females:Increased secretion of androgens causes development of male secondary sexual characters. The conditions is called adrenal virilism. The symptoms are:i. Masculinization due to increased muscular

growth.ii. Deepening of voice.iii. Amenorrheaiv. Enlargement of clitorisv. Male type of hair growth.

• Symptoms in males:Sometimes, the tumor of estrogen secreting cells produces more than normal quantity of estrogens in males. It produces some symptoms such as:i. Feminizationii. Gynecomastia (enlargement of breast)iii. Atrophy of testisiv. Loss of interest in women.

CONGENITAL ADRENAL HYPERPLASIA

• It is a congenital disorder characterized by increase in size of adrenal cortex.

• Size increases due to abnormal increase in the number of steroid secreting cortical cells.

Causes:• Even though the size of the gland increases,

cortisol secretion decreases.• It is because of the congenital deficiency of

the enzymes necessary for the synthesis of cortisol, particularly, 21 –hydroxylase.

• Lack of this enzyme reduces the synthesis of cortisol.

• It in turn, increases the secretion of ACTH from pituitary by feedback mechanism.

• ACTH stimulates the adrenal cortex causing hyperplasia with the accumulation of lipid droplets.

• Hence, it is also called congenital lipid adrenal hyperplasia.

• Cortisol cannot be synthesized because of lack of 21 –hydroxylase.

• Therefore, due to the constant simulation of adrenal cortex by ACTH, the secretion of androgens increases.

• It results in sexual abnormalities such as virilism.

Symptoms:• The characteristic features of adrenal

hyperplasia are virilism and excess body growth.• In boys: adrenal hyperplasia produces a

condition known as macrogenitosomia praecox.• The features of this condition are:i. Precocious body growth, causing stocky

appearance called Infant Hercules.ii. Precocious sexual development with enlarged

penis even at age of 4 years.

• In girls: in girls, adrenal hyperplasia produces masculinization.

• It is otherwise called virilism.• In some cases of genetic disorders, the female

child is born with external genitalia of male type. This condition is called pseudo -hermaphroditism.

HYPERALDOSTERONISM

• Increased secretion of aldosterone is called hyperaldosteronism.

Causes:• Depending upon the causes,

hyperaldosteronism is classified in to two types:

i. Primary hyperaldosteronism.ii. Secondary hyperaldosteronism.

i. Primary hyperaldosteronism.• It is otherwise known as Conn's syndrome.• it develops due to tumor in zona glomerulosa

of adrenal cortex. ii. Secondary hyperaldosteronism.• It occurs due to extra adrenal causes such as:1. Congestive cardiac failure2. Nephrosis3. Toxemia of pregnancy4. Cirrhosis of liver.

Signs and symptoms:i. Increase in ECF volume and blood volume.ii. Hypertension due to increase in ECF volume and

blood volume.iii. Severe depletion of potassium. Prolonged

depletion of potassium causes renal damage. The kidneys fail to produce concentrated urine. It leads to polyuria and polydipsia.

iv. Muscular weakness due to potassium depletion.v. Metabolic alkalosis due to secretion of large

amount of hydrogen ions into renal tubules. Metabolic alkalosis reduces blood calcium level causing tetany.

• Escape phenomenon:In primary hyperaldosteronism. Edema does not occur in spite of increased ECF volume. It is due to escape phenomenon, which involves pressure diuresis and ANP.

The end